Adentia is a complete or partial absence of teeth resulting from their loss or an anomaly in the development of the dental system. The disease is characterized by a violation of the continuity of the dentition, the function of chewing and speech, a cosmetic defect; in severe cases – deformation of the facial skeleton, TMJ diseases, further loss of teeth. Diagnostics is carried out by a dental specialist using visual and palpatory examination, targeted intraoral radiography, orthopantomography. Treatment consists in carrying out rational prosthetics with the help of partial or complete removable prostheses or dental implantation.
Adentia is a primary or secondary defect of the dentition, characterized by the absence of individual or all dental units in the oral cavity. This disease in dentistry is considered as a special case of an anomaly in the number of teeth, along with hyperodontia (over-complete teeth) and hypodontia (a decrease in their number compared to the norm).
Complete congenital adentia is extremely rare; the prevalence of partial adentia among dental anomalies in children is about 1%. Partial secondary adentia is found in 45-75%, and complete – in 25% of people over 60 years old. Adentia is not only an aesthetic defect, but is also accompanied by significant violations of the functioning of the dental system, gastrointestinal tract, deterioration of articulation and diction, psychological maladaptation, changes in human social behavior.
Causes of adentia
The primary pathology is based on the absence or death of the rudiments of teeth. In this case, the disease of the primary form can be caused by hereditary causes or develop under the influence of harmful factors acting during the formation of the dental plate in the fetus. Thus, the laying of the rudiments of temporary teeth occurs at 7-10 weeks of fetal development; permanent teeth – after the 17th week.
Complete congenital adentia is an extremely rare phenomenon that usually occurs with hereditary ectodermal dysplasia. In this case, along with the usual disease, patients usually have underdevelopment of the skin, hair, nails, sebaceous and sweat glands, nerves, eye lenses, etc. In addition to hereditary pathology, the primary form of the absence of teeth may be due to the resorption of dental rudiments under the influence of teratogenic factors, endocrine disruptions, infectious diseases; disorders of mineral metabolism in the prenatal period, etc. It is known that the death of dental rudiments can occur with hypothyroidism, ichthyosis, pituitary nanism.
The cause of the secondary disease is the loss of teeth by the patient in the process of vital activity. Partial absence of teeth is usually a consequence of:
- dental diseases: deep caries, pulpitis, periodontitis, periodontitis, removal of teeth and/or their roots, dental injuries;
- diseases of nearby tissues: odontogenic osteomyelitis, periostitis, pericoronitis, abscess or phlegmon;
- improper treatment: sometimes the cause of secondary adentia may be improperly performed therapeutic or surgical dental treatment (root apical resection, cystotomy, cystectomy).
In case of untimely orthopedic care, partial secondary adentia contributes to the progression of the process of tooth loss.
Depending on the causes and time of occurrence, there are primary (congenital) and secondary (acquired) adentia, as well as adentia of temporary and permanent teeth. In the absence of a dental germ, they speak of a true congenital form; in the case of a fusion of neighboring crowns or a delay in the timing of teething (retention), they speak of a false one.
Taking into account the number of missing teeth, the disease can be partial (some teeth are missing) and complete (all teeth are missing). Partial congenital adentia refers to the absence of up to 10 teeth (usually upper lateral incisors, second premolars and third molars); the absence of more than 10 teeth is classified as multiple adentia. The criterion for partial secondary adentia is the absence of 1 to 15 teeth on one jaw.
In the practice of orthopedic dentistry, the classification of partial secondary adentia according to Kennedy is used, which distinguishes 4 classes of dentition defects:
- I – the presence of a bilateral terminal defect (distally unlimited defect);
- II – the presence of a unilateral terminal defect (distally unlimited defect);
- III – the presence of a unilateral included defect (distally limited defect);
- IV – the presence of a frontal included defect (absence of front teeth).
Each class of partial secondary adentia, in turn, is divided into a number of subclasses; in addition, defects of various classes and subclasses are often combined with each other. There are also symmetrical and asymmetrical shapes.
Symptoms of adentia
Primary complete adentia occurs in both milk and permanent bite. With complete congenital pathology, in addition to the absence of dental rudiments and teeth, as a rule, there is a violation of the development of the facial skeleton: a decrease in the size of the lower part of the face, underdevelopment of the jaws, a sharp expression of the supramental fold, flat palate. There may be non-infection of the fontanelles and bones of the skull, non-fusion of the maxillofacial bones. With anhydrotic ectodermal dysplasia, adentia is combined with anhidrosis and hypotrichosis, the absence of eyebrows and eyelashes, pallor and dryness of the mucous membranes, early skin aging.
A patient with a primary complete form is deprived of the ability to bite and chew food, so he is forced to eat only liquid and soft food. The consequence of the underdevelopment of the nasal passages is mixed oral-nasal breathing. Speech disorders are represented by multiple violations of sound reproduction, in which the articulation of lingual-dental sounds is the most defective.
The main sign of partial primary adentia is a decrease in the number (shortage) of teeth in the dentition. Tremors form between adjacent teeth, there is a displacement of adjacent teeth into the area of dental defects, there is an underdevelopment of the jaws. In this case, the antagonizing teeth can be located crowded, outside the dentition, pile on top of each other or remain retinated. In the absence of teeth in the anterior group, interdental pronunciation of whistling sounds is noted. Tremors and incorrect position of the teeth can lead to the development of chronic localized gingivitis.
The secondary form in a milky or permanent bite is a consequence of the loss or removal of teeth. In this case, the integrity of the dentition is violated after the eruption of the formed teeth.
In the complete absence of teeth, there is a pronounced displacement of the lower jaw to the nose, sinking of the soft tissues of the oral region, the formation of multiple wrinkles. Complete adentia is accompanied by a significant reduction of the jaws – first osteoporosis of the alveolar processes, and then the body of the jaw. Often there are painless exostoses of the jaw or painful bone protrusions formed by the edges of the teeth holes. Also, as with primary complete adentia, nutrition is disrupted, speech suffers.
With secondary partial adentia, the remaining teeth gradually shift and diverge. At the same time, in the process of chewing, they have an increased load, while there is no such load in the areas of the adentia, which is accompanied by destruction of bone tissue.
Partial secondary adentia can be complicated by pathological tooth erasure, hyperesthesia, pain when teeth are closed, exposure to any mechanical or thermal stimuli; formation of pathological gingival and bone pockets, angular cheilitis. With a significant partial form, a habitual subluxation or dislocation of the temporomandibular joint may occur.
Cosmetic defects are characterized by changes in the oval of the face, pronounced nasolabial folds, chin fold, drooping corners of the mouth. In the absence of a group of frontal teeth, there is a “sinking” of the lips; with defects in the area of the lateral teeth, there is a hollowness of the cheeks.
Patients often have gastritis, gastric ulcer, colitis, and therefore they need not only the help of a dentist, but also a gastroenterologist. Tooth loss is accompanied by a decrease in a person’s self-esteem, psychological and physical discomfort, and a change in social behavior.
Adentia is a problem in the diagnosis and elimination of which dental specialists of various specialties take part: therapists, surgeons, orthopedists, orthodontists, implantologists, periodontists.
Diagnosis includes the collection of anamnesis, clinical examination, comparison of chronological age with dental, palpatory examination. In the presence of a local defect after the expiration of the teething period, targeted intraoral radiography is usually used to clarify the diagnosis. In case of multiple or complete loss of teeth, panoramic radiography or orthopantomography is performed, if necessary, radiography or CT of the temporomandibular joint.
X-ray examination allows to reveal the absence of rudiments of teeth, to detect gum-covered roots, exostoses, tumors of the oral cavity, to assess the condition of the tissue of the alveolar process, signs of inflammation, etc. At the stage of planning the treatment of adentia, casts are taken, production and study of diagnostic models of the jaws.
Treatment of adentia
The main method of eliminating adentia is prosthetics using fixed (bridge-shaped) orthopedic structures and removable dentures (clasp, plate, Acry-Free). The choice of the method of treatment of adentia is determined by the orthopedic dentist, taking into account the anatomical, physiological, hygienic features of the patient’s dental system.
Non-removable prosthetics involves the installation of supporting dental implants (mini-implants), on which the prosthetic structure is then attached (on 4, on 6 implants). With partial adentia, intact or well-healed teeth are used as support teeth. The method of choosing the elimination of secondary partial adentia is classical dental implantation with the installation of a crown, basal implantation.
Treatment of children can begin from 3-4 years of age. Orthopedic measures are reduced to the manufacture of complete removable plate prostheses, which in children should be replaced with new ones every 1.5-2 years.
Replacement of a removable prosthesis with a bridge is carried out only after the end of the growth of the jaws.
When using removable plate prostheses, there is a risk of prosthetic stomatitis, pressure sores of gingival tissues, allergies to dyes and polymers of the prosthesis material. Before starting treatment, complete professional oral hygiene is required, if necessary, complex treatment of caries, pulpitis, periodontitis, periodontitis, elimination of hyperesthesia of teeth, removal of roots and teeth that are not subject to preservation.
Prevention of congenital adentia in a child provides for the provision of favorable conditions for intrauterine development of the fetus, the exclusion of potential risk factors. If the regulatory deadlines for teething are delayed, it is necessary to contact a pediatric dentist.
Prevention of the secondary form is reduced to regular preventive dental examinations, hygienic measures, timely sanitation of pathological foci in the oral cavity. In case of loss of teeth, prosthetics should be performed as early as possible to avoid the progression of the disease.